18x8 and 18x9 wheel size. What is the widest you would recommend?

rezak1 · 08-17-2015, 10:34 AM

Hey guys, I'm very new to modifications and am looking for some advice on tire size. I'm looking to replace all four tires on my stock 2013 370z and currently, I have 18x8 wheels up front with 225 tires and 18x9 wheels in the back with 245 tires. I would like to get wider tires, especially in the back. What brand tires and sizes would you recommend without losing performance/stability? Thanks a bunch!

synolimit · 08-17-2015, 02:53 PM

You can 20% over and be safe. So rear can do 275 and front can do 245.

rezak1 · 08-17-2015, 06:13 PM

@synolimit I'm still new at this and was wondering how you arrived at those numbers. 20% of 225 is 45, so that would be closer to 265 in the front and closer to 295 in the back. Am I missing something? Thanks in advance

TN.Z · 08-17-2015, 06:19 PM

He is talking about 20% over wheel width.

9"+20%=10.8"
10.8"x25.4=274.32mm

Same math for the front just replace the 9 with 8 and you get 243.84

rezak1 · 08-17-2015, 07:14 PM

@TN.Z I see how you converted to mm from inches and the math you did there! That makes sense and thank you for the clarification!

TN.Z · 08-17-2015, 07:37 PM

Glad I could help. I am also looking for new tires for my base wheels in 245/45/18 and 275/40/18 but I can't really decide on summer or all-season.

jchammond · 08-17-2015, 08:02 PM

I run 245/45 & 275/40 Goodyears F1's all season. My son was driving car when it first needed tires & these perform well in wet weather.ImageUploadedByTapatalk1439859667.987239.jpg ImageUploadedByTapatalk1439859699.001514.jpg
Also both are factory 26.7" diameter

Sent from my iPhone using Tapatalk

jchammond · 08-17-2015, 08:34 PM

Quote:

Originally Posted by rezak1

@synolimit I'm still new at this and was wondering how you arrived at those numbers. 20% of 225 is 45, so that would be closer to 265 in the front and closer to 295 in the back. Am I missing something? Thanks in advance

i'm sure the wheels can stand a bit wider tire; but check close;as each tire maker can be as much as 1-2" different on same sizes,,,also think about if you want shorter or taller tires.
not sure the serie's tire's you are looking at/ the 295 is probably in a 35 series & barely over 26" tall ? Michelin PSS's are 10.8" tread,11.9"section & 26.1" diameter,,,that's on the 295/35
you would have a slight bulge for sure-not saying it won't fit though.

TN.Z · 08-17-2015, 08:35 PM

I am contemplating between those, Continental DWS, pilot sport A/S 3 (which are on my wife's 350z), or the new g-force comp-2 a/s. The last ones are very new and I can't find much info on them.

I do love my wife's tires so I will probably get the Michelins. My car currently has some Goodyear Eagle Sports and I HATE them.

TN.Z · 08-17-2015, 08:38 PM

Quote:

Originally Posted by jchammond

i'm sure the wheels can stand a bit wider tire; but check close;as each tire maker can be as much as 1-2" different on same sizes,,,also think about if you want shorter or taller tires.

not sure the serie's tire's you are looking at/ the 295 is probably in a 35 series & barely over 26" tall ? Michelin PSS's are 10.8" tread,11.9"section & 26.1" diameter,,,that's on the 295/35

you would have a slight bulge for sure-not saying it won't fit though.

But with a tread width that much wider than wheel width you aren't really going to get much better traction than you would with the 275 or 285... You are just paying more for bigger tires and a very very small performance gain.

rezak1 · 08-17-2015, 08:42 PM

Last question: What tire combo would you recommend? Does the following (0.9" stagger) look OK?
Front: 245/40/18
Rear: 275/40/18

jchammond · 08-17-2015, 08:43 PM

Bigger,Wider Tires weigh more...actually slow you down...unless you have very poor traction or ton's of power...i'm still stock for now.

jchammond · 08-17-2015, 08:45 PM

Quote:

Originally Posted by rezak1

Last question: What tire combo would you recommend? Does the following (0.9" stagger) look OK?
Front: 245/40/18
Rear: 275/40/18

looks good if you want your traction control light to pop on or even worse.

TN.Z · 08-17-2015, 08:47 PM

Quote:

Originally Posted by rezak1

Last question: What tire combo would you recommend? Does the following (0.9" stagger) look OK?

Front: 245/40/18

Rear: 275/40/18

Personally I'd stick with 26.7" diameter tires, 245/45/18 and 275/40/18.

I remember reading that having the front and rear diameters too far from each other can make the traction control think you are slipping.

Can someone confirm or deny this?

jchammond · 08-17-2015, 08:52 PM

Short video on traction with my F1's... Not going to post one hitting the speed limiter.https://vimeo.com/136571413

Sent from my iPhone using Tapatalk

08-17-2015, 10:34 AM	#1 (permalink)
rezak1 Base Member Join Date: Mar 2013 Location: Los Angeles Posts: 30 Drives: 2013-370Z-Black-MT Rep Power: 12	18x8 and 18x9 wheel size. What is the widest you would recommend? Hey guys, I'm very new to modifications and am looking for some advice on tire size. I'm looking to replace all four tires on my stock 2013 370z and currently, I have 18x8 wheels up front with 225 tires and 18x9 wheels in the back with 245 tires. I would like to get wider tires, especially in the back. What brand tires and sizes would you recommend without losing performance/stability? Thanks a bunch!

08-17-2015, 02:53 PM	#2 (permalink)
synolimit A True Z Fanatic Join Date: May 2013 Location: Columbus, OH Posts: 5,051 Drives: 2013 Silver 370z Rep Power: 3388	You can 20% over and be safe. So rear can do 275 and front can do 245. __________________ 13 370z-

08-17-2015, 06:19 PM	#4 (permalink)
TN.Z Base Member Join Date: Mar 2015 Location: Chattanooga TN Posts: 161 Drives: 09 BSM 6sp - 04 DBP Rep Power: 12	He is talking about 20% over wheel width. 9"+20%=10.8" 10.8"x25.4=274.32mm Same math for the front just replace the 9 with 8 and you get 243.84 Memphis370Z likes this.

08-17-2015, 07:14 PM	#5 (permalink)
rezak1 Base Member Join Date: Mar 2013 Location: Los Angeles Posts: 30 Drives: 2013-370Z-Black-MT Rep Power: 12	@TN.Z I see how you converted to mm from inches and the math you did there! That makes sense and thank you for the clarification! Jozisworld likes this.

08-17-2015, 07:37 PM	#6 (permalink)
TN.Z Base Member Join Date: Mar 2015 Location: Chattanooga TN Posts: 161 Drives: 09 BSM 6sp - 04 DBP Rep Power: 12	Glad I could help. I am also looking for new tires for my base wheels in 245/45/18 and 275/40/18 but I can't really decide on summer or all-season. Jozisworld likes this.

08-17-2015, 06:13 PM	#3 (permalink)
rezak1 Base Member Join Date: Mar 2013 Location: Los Angeles Posts: 30 Drives: 2013-370Z-Black-MT Rep Power: 12	@synolimit I'm still new at this and was wondering how you arrived at those numbers. 20% of 225 is 45, so that would be closer to 265 in the front and closer to 295 in the back. Am I missing something? Thanks in advance

08-17-2015, 08:02 PM	#7 (permalink)
jchammond A True Z Fanatic Join Date: Nov 2014 Location: South Carolina Age: 57 Posts: 15,204 Drives: 13’ 370Z TS 7A/T Rep Power: 2684394	I run 245/45 & 275/40 Goodyears F1's all season. My son was driving car when it first needed tires & these perform well in wet weather.ImageUploadedByTapatalk1439859667.987239.jpg ImageUploadedByTapatalk1439859699.001514.jpg Also both are factory 26.7" diameter Sent from my iPhone using Tapatalk Jozisworld likes this. __________________ MazWorx built long block \| FI-TT-100 Stage 2.75 \| IPT built 7A/T http://www.the370z.com/members-370z-...s-musings.html

08-17-2015, 08:35 PM	#9 (permalink)
TN.Z Base Member Join Date: Mar 2015 Location: Chattanooga TN Posts: 161 Drives: 09 BSM 6sp - 04 DBP Rep Power: 12	I am contemplating between those, Continental DWS, pilot sport A/S 3 (which are on my wife's 350z), or the new g-force comp-2 a/s. The last ones are very new and I can't find much info on them. I do love my wife's tires so I will probably get the Michelins. My car currently has some Goodyear Eagle Sports and I HATE them.

08-17-2015, 08:42 PM	#11 (permalink)
rezak1 Base Member Join Date: Mar 2013 Location: Los Angeles Posts: 30 Drives: 2013-370Z-Black-MT Rep Power: 12	Last question: What tire combo would you recommend? Does the following (0.9" stagger) look OK? Front: 245/40/18 Rear: 275/40/18

08-17-2015, 08:43 PM	#12 (permalink)
jchammond A True Z Fanatic Join Date: Nov 2014 Location: South Carolina Age: 57 Posts: 15,204 Drives: 13’ 370Z TS 7A/T Rep Power: 2684394	Bigger,Wider Tires weigh more...actually slow you down...unless you have very poor traction or ton's of power...i'm still stock for now. __________________ MazWorx built long block \| FI-TT-100 Stage 2.75 \| IPT built 7A/T http://www.the370z.com/members-370z-...s-musings.html

08-17-2015, 08:52 PM	#15 (permalink)
jchammond A True Z Fanatic Join Date: Nov 2014 Location: South Carolina Age: 57 Posts: 15,204 Drives: 13’ 370Z TS 7A/T Rep Power: 2684394	Short video on traction with my F1's... Not going to post one hitting the speed limiter.https://vimeo.com/136571413 Sent from my iPhone using Tapatalk __________________ MazWorx built long block \| FI-TT-100 Stage 2.75 \| IPT built 7A/T http://www.the370z.com/members-370z-...s-musings.html

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